Il Nuovo Cimento (1955-1965)

, Volume 38, Issue 2, pp 807–816 | Cite as

The hyperfragment7HeΛ



A factor contributing to the apparent binding-energy difference between7HeΛ and7BeΛ is the possibility of the existence of an isomeric state for7HeΛ. A shell-model calculation has been performed for theE2, decay rate from this conjectured state and the results suggest a lower limit of 10−9 s for the lifetime. Comparison with estimates of the A decay lifetime for7HeΛ adds weight to the existence of the isomeric state.


Un fattore che contribuisce all’apparente differenza deU’energia di legame fra7Heλ e7BeΛ `e la possibile esistenza di uno stato isomerico del7Heλ. Si è effettuato, in base al modello a strati, un calcolo del rapporto di decadimentoE2 da questo ipotetico stato ed i risultati suggeriscono per la vita media un limite inferiore di 10−9s. Il confronto con le valutazioni del periodo medio del decadimento Λ del7HeΛ dà peso all’ipotesi dell’esistenza di questo stato isomerico.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. (1).
    R. Levi-Setti ;Proceedings of the International Conference on Hyperfragments (CERN 64-1).Google Scholar
  2. (2).
    R. H. Dalitz:The Nuclear Interactions of the Hyperons (EFINS-62-9).Google Scholar
  3. (3).
    M. Raymund: (EFINS-63-63).Google Scholar
  4. (4).
    D. H. Wilkinson:International Conference on High-Energy Physics and Nuclear Structure (CERN 1964).Google Scholar
  5. (5).
    A. R. Bodmer andJ. W. Murphy:The p-Shell Hypernuclei and the ΛNinteraction (university of Manchester, Preprint 1964).Google Scholar
  6. (6).
    J. Pniewski andM. Danysz:Phys. Lett,1, 142 (1962).ADSCrossRefGoogle Scholar
  7. (7).
    E. H. Dalitz:The Strong and Weak Interactions of Bound Λ Particles (EFINS-63-29).Google Scholar
  8. (8).
    R. H. Dalitz: Private communications.Google Scholar
  9. (9).
    R. J. Prem andP. H. Steinberg: (Tech. report 363, University of Maryland.Google Scholar
  10. (10).
    L. R. B. Elton:Phys. Lett.,2, 41 (1962);5, 96 (1963). The calculations in these papers were a factor 2π out. When corrected the lifetime is 5.5-10-10s.ADSCrossRefGoogle Scholar
  11. (11).
    M. A. K. Lodhi: Private communication.Google Scholar
  12. (12).
    J. M. Blatt andV. F. Weisskopf:Theoretical Nuclear Physics (New York, 1955).Google Scholar
  13. (13).
    G. E. Brown:Lecture on Many-Body Problems (Nordita 1962);B. R. Easlea Lecture on Many-Body Problems (Pittsburg, 1963);D. J. Thouless:Many-Body Problem (New York, 1961).Google Scholar
  14. (14).
    V. Gillet:Nucl. Phys.,51, 410 (1964).CrossRefMATHGoogle Scholar
  15. (15).
    J. M. Soper:Phil. Mag.,2, 1219 (1957).ADSCrossRefGoogle Scholar
  16. (16).
    A. R. Edmonds:Angular Momentum in Quantum Mechanics (Princeton, 1957).Google Scholar
  17. (17).
    K. W. Ford andE. J. Konopinski:Nucl. Phys.,9, 218 (1958).CrossRefGoogle Scholar
  18. (18).
    D. C. Peaslee:Phys. Rev.,124, 839 (1961).ADSCrossRefGoogle Scholar

Copyright information

© Società Italiana di Fisica 1965

Authors and Affiliations

  • J. Law
    • 1
  1. 1.Physics DepartmentBattersea College of TechnologyLondon

Personalised recommendations